Science Work and Vehicle Departure Preps Under Way for Expedition 39

The six residents aboard the International Space Station are busy conducting an array of science to benefit life on Earth and in space. Meanwhile, two spacecraft are being readied for their upcoming departures before the end of the month.

NASA astronauts Rick Mastracchio and Steve Swanson are working on a pair of new plant science experiments delivered aboard the SpaceX Dragon commercial cargo craft.

Commander Koichi Wakata looks out the Cupola.

Mastracchio worked throughout the morning on the Gravi-2 experiment which observes how plant roots grow in microgravity. He set up a camera to record Gravi-2 operations, hydrated culture chambers and assembled science gear inside the BioLab Glovebox.

Swanson worked during the day on the Veggie investigation setting up hardware and conducting onboard training for the botany study. That experiment studies the feasibility of growing vegetables in space, using lettuce as a test case, for consumption by future crews. The lettuce will be harvested in space, stored in a science freezer and returned to Earth for analysis. Veggie will begin scientific operations Thursday.

Japanese astronaut and Expedition 39 Commander Koichi Wakata downloaded data collected for the Circadian Rhythms study. He wore Circadian Rhythms gear that measured how his “biological clock” is adapting to a long-term spaceflight mission. The normal 24-hour cycle a human on Earth experiences is different than what an astronaut experiences which is a sunrise and sunset every 90 minutes in low-Earth orbit.

Flight Engineer and Soyuz Commander Mikhail Tyurin worked throughout Wednesday on crew departure preparations. He, Mastracchio and Wakata will return to Earth May 13 and land in Kazakhstan inside the Soyuz TMA-11M vehicle. He loaded cargo inside the Soyuz spacecraft docked to the Rassvet module and updated the station’s inventory management system.

Cosmonauts Alexander Skvortsov and Oleg Artemyev began their day on a couple of Russian science experiments. Skvortsov activated an incubator for the Conjugation study which is investigating new techniques to design drugs. Artemyev downloaded data collected for the Obstanovka experiment which observes how the spaceflight environment affects facilities and hardware on the space station.

The SpaceX Dragon resupply ship is due to complete its mission May 18 when the Canadarm2 unberths and releases it from the Harmony node. Swanson is replacing a bolt on Harmony’s earth-facing Common Berthing Mechanism to ensure Dragon’s departure and Cygnus’, Orbital Sciences second commercial cargo craft mission, arrival on June 13. The last external experiment, the OPALS laser study, has been removed from Dragon’s trunk with the Canadarm2 and will be installed on the External Logistics Carrier-1 attached to the station’s far port truss.